Machine for testing yarn



Oct. 26, 1937.

.J. P LAETSCH MACHINE FOR TESTING YARN Filed Dec- 15, 1933 2 Sheets-Sheet 1 \& nu

Oct. 26, 1937. J, p LAETSCH 2,097,086

7 ncnms FOR 'ras'rme YARN Filed Dec. 15, 1935 2 Sheets-Sheet 2 ,qaz F763. 54'

JP HM Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE Application December 15, 19:3, Serial No. 102,012 In Germany December 22, 1932 12 Claims.

This invention relates to means for testing the strength and uniformity of yarns by the rupture of pieces of thread of a definite length. By the methods at present usual yarns are tested in such a way that the breaking strength or rupture force is continuously noted, and first the principal mean, that is to say, the mean breaking value is found. In addition to this the percentage deviation of the sub-mean is compared, that is to say, the mean. of all those values which are below the principal mean. This furnishes a measure of the quality of the product. This method of measuring, however, only enables a judgment to be formed with diihculty with respect to the behavior of the yarn in its further treatment. In this further treatment the uniformity' of the breaking strength is of the utmost importance. A yarn of good average breaking strength may contain individual low breaking values which lead to stoppages during the succeeding operations, whereas a weaker yarn, in which however the breaking values do not differ widely from the principal mean, is greatly to be preferred in this respect.

Appliances for carrying out the testing of yarn, which record breaking values automatically upon strips of paper are already known. They record these, however, only in the time sequence in which they occur. This method of recording does not enable the minimum values to be recognized at first glance. In order to deter-mine the mean breaking force and the mean elongation, a calculation always hasto be made. Hence a considerable expenditure of time is required for carrying out the known testing processes, and even then the result may be doubtful owing to errors of calculation. Furthermore only the count before and after the breaking tests can be determined, whereas what is of special importance is the knowledge of the count of the yarn actually broken.

Now the present invention is distinguished by the fact that the breaking values are automatically recorded according to their frequency and their order of magnitude. For this purpose a recording. appliance is provided, and also devices which add up and indicate the individual'breaking values and elongations.

By this means the minimum breaking values that are unsafe for the further treatment of the thread can be immediately recognized, and the yarn can easily be Judged in this particular. rmthe determination of the mean breaking strength and elongation, calculation is no longer required. This results in a saving of time and in the elimina tion of a source of error.

The invention further provides an automatic drawing in or feeding and breaking device, which is so designed that. the feeding and breaking of two different pieces of thread are effected simultaneously. By this arrangement the number of breaking operations per unit of time can be considerably increased as compared with known apparatus.

Finally, the invention also provides a device which collects the broken pieces of thread for the purpose of determining the count of yarn from the weight, and also for determining if desired the percentage of moisture contained therein. In this manner the count of the yarn actually broken is obtained, and therefore the quality of the product tested may be definitely determined with much greater certainty.

One form of construction according to the invention is illustrated by way of example in the accompanying drawings, in which Figure l is a perspective front view of the apparatus according to the invention,

Figure 2 is an end view of details, partly in section,

Figure 8 shows a section on the line III-J11 in F gure 2,

Figure 4 is a diagram made by the apparatus according to the invention, and

Figure 5 shows further co-operating parts of the apparatus in end elevation, partly in section.

In Figure 1, I denotes a shaft driven by a motor, not shown at a uniform speed of revolution, 2 a cylinder mounted on this shaft to rotate therewith and provided with acam groove, and I a slide reciprocated by this cylinder and guided on rods 4 and I rigidly mounted in the frame (not shown) of the machine. The slide I is connected by a link 0 with a feeding arm I, which is rockable about a pivot I mounted in the frame of the machine. The piece of thread to be broken, which is indicated by 9, is clamped between two rupture clamps II and II, of which the clamp is fitted to the slide 3, and the clamp I! to a lever ll, hereinafter referred to as the rupture lever, pivoted on a stationary shaft. The lever "carries an adjustable weight II, and isconnected at the end of its short arm, by a tensile member I, a steel band for example, with the short arm I. of a lever It pivoted on a stationary shaft it" and loaded by a weight The lever I. will be hereinafter referred to as'the recording lever. The short arm of the recordinglever is in the shape of an eccentric, upon the periphery of which the steel band It is secured at It, and it is so constructed that when therecording lever rotates through equal arcs, the tensile force applied to the thread during the loading likewise increases by equal amounts, that is to say, according to a straight-line law. The recording lever is resiliently constructed in its upper portion l1, and carries a pin ll. The

part II may consist of a resilient strip which as can be moved against a recording device by the following means. A frame consisting of two side arms pivoted a substantial distance apart on the shaft 5 and connected by rods and 32, is oscillated by a cam l8 on the shaft 5, contacted by an extension of one'of the side arms. The upper portion of the recording lever ll passes just inside the rod 20 of the frame and upon oscillation of the latter is pressed against a recording device to be described later or allowed to move out of contact therewith by its own resiliency. The recordingdevice consists essentially of a recording cylinder 2|, which is composed of individual toothed discs 22, and also of a number of slotted switching members 23 pertaining to the individual toothed discs and mounted through the slots upon a rod 23' resting in bearings in the frame of the machine, and ofa diagram cylinder 24 co-operating with the recording cylinder.

' means.

Figures 2 and 3 show details of the recording The tootheddiscs 22, which are provided with teeth on part only of their peripheries, are rotatably mounted upon a shaft 25, with the interposition of discs or washers 26. 'The washers are connected with. the shaft by a projection er engaging in a corresponding groove or key-way in the shaft, and prevent the adjacent discs from being carried round when, onetcothed disc revolves. A spring 28, whichpresses thediscs together, provides that they can only be rotated by a certain force. By means ofa nut 29,whi ch bears against the discsby means of sleeves 38 and ill, these discs can be connected fast with the shaft 25, by being pressed against the crank .33 which is likewise keyed on to the shaft 25. The sleeves to and 30' are'supported in bearing supports 39 and 32. There is keyed on the sleeve dllflwhich'is rotatable with the shaft 25, a-toothed wheel at which engages in a second toothed wheel 35 mounted on a shaft 36' and connected rigidly th the diagram cylinder (id in Fig. 1). As shown in Fig. 3, the diagram cylinder consists of two discs 31, which receive between them an indie rubber cylinder 36, and which are provided with fastening members, for instance pins 38, for the diagram sheet 33, which fits over a portion of the periphery. The remainder of the periphery between the positions a and b is recessed and is of smaller radius than the part intended for the diagram. The shaft 35' of the India rubber roller is slidably supported in the bearing supports. It is subject to the action of springs '40 which draw it toward the shaft 25 and which are designed as spiral springs as shown in Fig. 3 and are secured at one end at 46' to the bearing supports while the other end engages with the shaft 36' at 40,. The

toothed discs 22 and the switching members as occupy the position indicated in Figure 2 before the apparatus is started, so that the toothof each switching member. engages in the first gap between the teeth of thetoothed disc at the posi- In the movement of the slide 3 towards the 7 right caused by rotation ofthe shaft l the breaking lever ll) is taken along by the pull of the piece of thread 9. Under the action of the pulling member ll, the recording lever is, l|,with its a pawl 4| connected with said lever, as herein after more fully described, and thereupon said lever is moved by the rod 20 against the recording cylinder, so that the pin l8 displaces a corresponding switching member 23 so far that the associated toothed disc 22 is rotated to the extent of one tooth in a clockwise direction. Thereupon the rod 20, and the rod '42, described above connected with it and parallel to it, are rocked back under the action of the cam disc IS, the rod 42 bearing against the switching member 23 and sliding the latter back into its initial position. A fresh breaking test and corresponding recording may now be effected, the individual toothed discs corresponding to the breaking forces that occur being fed one tooth forward from time to time in this manner. The teeth on each disc that are fed forward constitute a measure of the frequency of the breaking force that corresponds to this disc. After the device has'broken a ratherlarge number of pieces of thread, the nut 29 is tightened up in order that the toothed discs may be pressed together, and connected with the shaft ,25, and thereupon the recording cylinder is rotated by the crank 33, the diagram cylinder also being carried round with it. During this rotation the two cylinders roll over one another and all the teeth that have been. fed forward on the toothed discs are Pu hed into the diagram sheet, as shown in Figure 4, under the action of. the springs 49. The arrangement is such that the base line b of the diagram coincides with the point b, indicated in'Figure 2. All. the teeth that have not beenfed forward, which are located before the rotation of the crank to the left of the position 0 or of the line III-III, cannot make any mark upon the diagram sheet when the crank rotates, since the two cylinders roll upon one another and the teeth that have not been fed forward only strike behind the edge 22, that is, in the recess. ,According to the drawings, each toothed disc has thirty teeth. Now if it is usumed that a disc would be fed forward thirty timeathe first tooth would'be displaced from e to the positiond. Upon rotation of. the crank this tooth would first come into contact with the diagram sheet at the line 30 in Figure 4. The abscissa is divided into groups and indicates the rupture forces in grams. The scale of the diagram may of course be varied at will by adjustingor putting on weights, for'instance, by adjusting the weights l5 and i3. 1 V

The advantages of this diagram representation are obvious. The diagram produced shows at a glance the magnitude and the number of the minimum values thatnare unsafe for further treatment. The shape of the surface formed by the tooth impressions is an obvious measure of the uniformity of. the yarn tested; The broader this surface is and the more peaks it shows, the less uniform is the material tested. It is important that the diagram according to Figure 4 can be produced by the apparatus according to the invention merely by rotating a crank 33, and that by rotating it a number of times the diagram can be duplicatedasfrequently as may be desired. v

. Since the mean breaking force cannot be accurately read off from the diagram there is connected with the recording lever l6, I'La device which adds up and indicates the breaking forces occurring. For this purpose there is rotatably arranged upon the pivot of the recording lever a ratchet wheel 43, with which there engages the pawl 4|, and a detent ll. The pawl II is rotatably mounted on a bell-crank lever 1'! which is connected at e to the recording level I. and adapted to bear against a stop It on the recording lever. At the commencement of the breaking operation, therecording lever moves towards the right, and at the moment when the thread breaks, the pawl ll snaps into the ratchet wheel 43, which is held fast by the detent 44, and thereby prevents the recording lever'from swinging back. At the end of the movement of the slide towards the left. the feeding arm 8 .releases the detent 44, and the recording lever falls back into its initial position, and in so doing rotates the ratchet wheel I! in an anti-clockwise direction through an angle corresponding to the magnitude of the breaking force. A pointer ll is secured to the lever II which moves according to the value of the breaking force. Consequently, after each stroke, the actual value of the breaklng force is indicated on the corresponding scale. Rotatably mounted wheels 43 and Cl are mounted on the bearing pivot I!" of the lever I 6. A pawl engages the wheel and is connected in a special manner as hereinafter explained with the recording lever It so that it takes the wheel II with it during a movement of the lever I. (Fig. 1) to the left. When the lever It returns to the initial position after each stroke (i. e. when the lever it moves to the left), the pawl ll rotates the wheel 43 to the extent of the stroke. This rotation is transmitted at a reduced speed of '100 times over wheel 45, an endless chain 46 or the like and wheels 41, 4| to a pointer 49. The pointer 49 continuously records on its scale the values of the breaking force. The resultant sum of all breaking forces gives the mean value if 100 tests are always made.

The'mean extension is indicated in a similar manner, as hereinafter explained, through transmission elements 00. to 88 by apointer ll.

It is obvious that one can also work with lea than 100 tests. The mean value of the breaking force or extension is then determined by a simple calculation, that is to say by dividing the indicated sums by the number of txts.

The feeding or drawing in of the thread 5| coming from'a bobbin Ii is effected by the drawing-in arm I by means of a clip 02. The clip, which will hereinafter be more fully described, is closed by an abutment N in the left hand end position of the feed arm. In the right hand end position it is opened by a stop I. Figure 1 shows the drawing-in arm in the left hand end position. The thread BI is here seized by the clamp 82, and, as the slide moves towards the right, is drawn into the holding clips 55 and I. of the reaching arms 51 and it. These reaching arms are the long arms of angular levers mounted on the shaft I. The short arms of these levers rest on earns 66 and I mounted on the shaft I which thus actuates the reach arms 51 and I0. Upon the clip 52 striking against the abutment It the clip is opened. and the drawing-in armis thereupon moved back into its left hand end position for re-engagement.

Shortly before the slide reaches its left hand end position the breaking clamps ii and I2. which are more fully described below, are opened by means of cam discs II and Oil mounted on shaft i, the pieces of thread are brushed out of the clips by rotating brushes I and 82 driven by the shaft i as clearly shown in Fig. 1 and are conveyed'to stripping devices 63, it, which let the threads fall into receptacles 65, only one of which is shown in the drawings. I

The stripping device consists mainly of a support of wood or iron, on which so called stripping clothing, as is used for cards, is secured. ti and II are brushes having hogs bristles wherein the thread is caught after the rupture. The brush with the thread now passes from above, as indicated by the arrow in Fig. 1, over the stripping clothing, to which the threads adhere. Owing to the continuous downward movement of the brushes, the threads are finally wound into balls and occasionally drop down from the clothing in lumps.

As soon as the broken pieces of thread have been removed from the rupture clips, the fresh piece of thread already drawn in, is placed in the open breaking clips by a rocking movement of the reaching arms I! and 58, effected by means of the cams SI and", and shortly afterwards the clips close.

It is important that the drawing of the thread into the reaching arms 51 and II should occur simultaneously with the breaking of the piece of thread 9 already clamped in the breaking clips II and I2.

This special arrangement, and also the circumstance that the apparatus is driven continumany and uniformly, and consequently permits of a comparatively high speed of the breaking clips II and II, which is not hindered by the damping means usual in other apparatus, enable the number of breaking tests per unit of time to be made much greater in practice than has hitherto been Possible.

The collecting device indicated by I, 8!, 63 and N for the broken pieces of thread is provided for the purpose of determining the yarn count by weighing these pieces. Hereby a valuable check upon the count of yarn is rendered possible. Furthermore the percentage of water in the broken threads can be determined, and this, as is known, considerably influences the ultimate strength of the thread.

In order to cut of! the thread after it has been drawn in, there is provided upon the shaft I a cam disc II which actuates a pair of shears Us. From Figure 5 the construction and the co-operation of the clips can be seen.

The clip I! consists of two clamping members I! and II, which are rotatably arranged upon a bolt or pin 86 mounted on the lever B, and are held together by a spring 90. In the bolt 88 is inserted a little pin OI, which in its turn runs in a groove 02 in the clamping member 08. When the clamp member '80 strikes with its extension ll against the abutment ll, shown in Figure 1, the clip opens, that is to say, the member 88 moves away from the member 01 until the little pin ll enters the end 08 of the groove 82, which is perpendicular to the bolt ll. The litte pin can therefore no longer snap back, notwithstanding the opposing force of the spring 00. Again when the clamp member strikes the abutment ll (Fig. 1) the clamping member 09 then undergoes an opposite movement.

The spring comes into action, and the thread II is nipped, and is pulled by the drawing-in arm I into the funnel-shaped clamps of the reaching arms Il, ll. The thread is held fast between the end 84 of the reaching arm and the member 00 loaded by a weak spring 85. The reaching arms 51 and It, controlled by the cam discs I, I1, convey the thread towards the rupture clamps l2 and II. These are mounted one on the end of the rupture lever Ill and one on the slide 8. Their structure and operation is shown in Pig. 5. The relatively stationary element ll of each forms a clamp with the movable piece 91, which clamp is held closed by a spring 99 and opened by a cam 59 or 60 mounted on the shaft I.

As the reaching arms deliver the thread to the rupture clamps the eccentrics 59 and 69 come into contact with the clamping pieces 91 and open the clamp. Due to rotation of the eccentrics however, the pressure upon the clamping piece 91 ceases, a spring 99 pulls it back into the original position, and the thread is now firmly clamped.

Since in the testing of yarns in general the extension is also ascertained, there is provided for this purpose a device which determines and indicates the sum of the extensions. This device consists of a pawl 69, which is mounted on the rupture lever, and which engages in a ratchet wheel 10 arranged upon the pivot of the rupture lever, a toothed wheel H arranged beside the ratchet wheel, with a pawl 12, and a toothed rack 13, which co-operates with the toothed wheel, and which is pulled by a spring 14 and held by a stationary detent 15. A further pawl 16 on the slide 3, which can likewise engage in the rack 13 and a bell-crank lever 11 pivoted to the recording lever H5 at e and carrying the detent 4l, are provided for the device for measuring the extensions.

For measuring the extensions two different magnitudes are ascertained, namely the stroke of the rupture lever clip I2 and the residual stroke traversed after the breakage of the thread by the rupture clip II on the slide. The sum of these two magnitudes is equal to the difference between the total slide. stroke and the extension of the thread. These magnitudes are indicated in the following manner:

Upon breakage of the thread the lever [6 has a tendency to return to its initial position under the action of the weight l5. This is, however, prevented by the dropping of the pawl 4!, which is mounted on the bell-crank lever 11, into the wheel 43 secured bythe pawl 44. Since the long arm of the bell-crank lever bears during the breaking movement of the carriage through gravity on the pawl 16 and the short arm of the bellcrank lever does not therefore come in contact with thestop 18, the bell-crank lever is swung about the pivote until its short arm bears on the stop 18. By this swinging movement the long arm of the bell-crank lever, which normally holds the pawl 16 out of engagement, is raised so far that the pawl 16 drops into the rack 13 and the latter is therefore moved ,towards the right through the residual stroke of the slide. During this movement the toothed wheel H, with the pawl 12, is moved in a clockwise direction, and the spring 14 is stressed, the pawl 15 preventing the rack 13 from slipping back. Upon the rev to the stroke of the rupture clamp I2.

turn of the slide 3 its end portion 19 releases the pawl 15, so that under the action of the spring I4 the ratchet wheel H is rotated, and by means of a pawl 12 the ratchet wheel 10 is also rotated. A pointer 84 connected with the ratchet wheel Ill through the transmission elements 80, Si, 82 and 83 therefore indicates first the residual stroke of the rupture clamp ll. Previously, however, the ratchet wheel Hi, after the breakage of the thread, when the rupture lever i9 falls back, is rotated by the pawl 69 through an angle which corresponds This stroke als'ois likewise indicated by the pointer 84. Now when 100 lengths of thread are tested, the distance between I and g on the scale for pointer 84 is made to correspond to 100 entire strokes of the slide 3. Then the part of the scale to be read between the scale mark g and the tip of the pointer represents the total extension, so that here again in one hundred measurements the mean value, that is to say, the mean extension, is indicated.

The entire apparatus described above indicates the important test values in an entirely automatic manner, and only a zero testing of the indicating device or a zero reading is required, and, after the apparatus has been working automatically for some time, a rotation of the crank 33 for the production of the diagram, and a reading of indicating appliances, are necessary. In order that the operator may secure information concerning the number of pieces of thread already broken, and concerning the number of pieces still to be tested, a counting device is provided, consisting of an abutment 85 on the slide, and a lever 86' actuated thereby, with a feed pawl or detent 81', a ratchet wheel 88' and a pointer 99. A spring Hill is also provided for drawing the arm 86' into its starting position which may be limited by a fixed abutment llll.

The recording device according to the invention is not restricted to the use in machines for testing yarns but may also be employed for other purposes, for example, in cases wherein frequency operations are to be recorded.

What I claim is:--

l. -In a machine for testing the tensile strength uniformity of threads of definite length, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of counting members arranged in juxtaposition, a lever, means for positioning said lever successively along said row in accordance with the tensile strength of each piece of thread, and means causing said lever after the breakage of each thread to advance aunit distance the feed of that counting member which corre-- sponds in its position to the position of said lever.

2. In a machine for testingthe tensile strength uniformity of successive pieces of thread of deflnite length, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of counting members arranged in juxtaposition, a feeding means for each counting member, a lever, means for positioning said lever successively along said row in accordance with the tensile strength of each piece of thread, means to move the lever into contact with a feeding means to advance the corresponding counting member at the termination of the test of each piece of thread, and a diagram marking device connected with the recording device.

3. In a machine for testing the tensile strength uniformity of successive pieces of thread of definite length, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of rotatable toothed discs forming a roller, a feeding means for each disc, a lever, means for positioning said lever successively with its end portion along the toothed disc roller in accordance with the tensile strength of each piece of thread, means to move the lever into contact with a feeding means to advance the corresponding toothed disc at the termination of the test of each piece of thread, and a diagram marking device connected with the recording device.

4. In a machine for testing the tensile strength uniformity of successive pieces of thread of a definite length by means of a weight loaded rupture lever carrying a thread clamp, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of counting members arranged in juxtaposition, a recording lever, means for positioning said recording lever successively along said row in accordance with the tensile strength of each piece of thread, and a pulling member connecting the recording lever with the said rupture lever.

5. The device as claimed in claim 4, in which the recording 'iever has an extension of excentric shape serving for the fixing of the pulling member thereto.

6. In a machine for testing the tensile strength uniformity of successive pieces of thread of a definite length, a recording device for indicating the strength rupture values of the threads in order of magnitude and recurrence frequency, comprising a row of toothed discs forming a roller, a lever, means for positioning said lever successively along said toothed disc roller in accordance with the tensile strength of each piece of thread, a feeding means comprising a row of pawls engaging in the toothed discs andtwo jointly rockable feeding rods parallel to the toothed disc roller, adapted to press the recording lever against a pawl to feed the corresponding toothed disc and to subsequently return the pawl to its initial position.

7. In a machine for testing the tensile strength uniformity of pieces of thread of a definite length, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of rotatable toothed discs toothed only upon a portion of their periphery, a recording lever, means for successively positioning said lever along said row in accordance with the tensile strength of each piece of thread, means causing said lever after breakage of each thread to rotate the corresponding disc a unit amount, a rotatable shaft and crank for the toothed discs, means for connecting the toothed discs fast to the shaft and a cylinder for carrying a diagram sheet thereon, and means for rotating this cylinder and the toothed discs in unison for the purpose of pressing the teeth of the toothed discs which have been advanced by said recording lever into the diagram sheet.

8. In a machine for testing the tensile strength uniformity of pieces of thread of a definite length, a recording device for indicating the strength values of the threads in order of magnitude and recurrence frequency comprising a row of rotatable toothed discs toothed only upon a portion of their peripheries, a recording lever, means for successively positioning said lever along said row in accordance with the tensile strength of each piece of thread, means causing said lever after breakage of each thread to rotate the corresponding disc a unit amount, a rotatable shaft and crank for the toothed discs, coupling discs on the rotatable shaft between the toothed discs, a clamping nut on the end of the shaft for pressing the toothed discs and coupling discs together, and a cylinder for carrying the diagram sheet, said lastv named cylinder being adapted to be rotated with the toothed discs for the purpose of pressing the teeth of the toothed discs which have been advanced by said recording lever into the diagram sheet.

9. In a machine for testing the strength uniformity of successive pieces of thread of a definite length, a recording device for arranging the tensile strength values of the threads in order of magnitude and frequency comprising a row of counting members arranged in juxtaposition, a weight loaded recording lever, means for positioning said lever successively along said row in accordance with the tensile strength of each piece of thread, and means causing said lever after the breakage of each thread to rotate the corresponding counting member a unit amount, and an indicating device comprising a ratchet wheel upon the pivot of said recording lever, said indicating device being driven by the ratchet wheel by the aid of a transmission and a detent on the recording lever engaging the ratchet wheel and adapted to advance the ratchet wheel when the recording lever falls back after breakage of a thread.

10. In a machine for testing the tensile strength uniformity of successive pieces of thread of definite length, a reciprocating slide, a test clamp thereon, a weight-loaded test lever carrying a second test clamp, two rockable reaching arms with holding clamps at the ends, and a drawing-in arm connected with and movable by the slide, the drawing-in arm being adapted with the testing movement of the slide to draw in a piece of thread so that the rupture of a piece of thread and the drawing-in of a new piece of thread into the holding clamps of the reaching arms take place simultaneously.

11. In a machine for testing the tensile strength uniformity of successive pieces of thread of definite length. a reciprocating slide, a test clamp on the slide, a weightloaded test lever, a second test clamp carried by the test lever, two rockable reaching arms, holding clamps at the ends of the reaching arms, a rockable drawing-in arm for the simultaneous drawing in of a new piece of thread during the testing movement of the slide, a tension rod connecting the drawing-in arm with the slide, a thread clamp at the end of the drawing-in arm, and stationary abutments at the ends of the stroke of the drawing-in arm in the path of the thread clamp for opening and closing this clamp.

12. In a machine for testing the tensile strength uniformity of successive pieces of thread of definite length, a reciprocating slide,

a test clamp on the slide, a weight-loaded testing lever mounted to cooperate with said slide, a second test clamp carried by the testing lever holding the thread during the testing movement of the slide, two rockable reaching arms, a drawing-in arm connected with the slide. the drawingin arm being adapted, during the testing of one piece of thread, to draw a fresh piece of thread into the holding clamps of the reaching arms, a driving shaft, and a plurality of cam discs arranged on the driving shaft to control the testing clamps and reaching arms, and a cutting device for cutting off the piece of thread to be tested.

JOI-IANN PAUL LAETSCH. 

